1. Field of the Invention
The invention relates to a vehicle battery diagnosis system and, more particularly, to a vehicle battery diagnosis system that diagnoses the state of degradation of a battery of a vehicle equipped with the battery as a motive power source.
2. Description of the Related Art
In recent years, taking into consideration environmental issues such as global warming and the like, the development of vehicles equipped with a battery as a motive power source, such as electric motor vehicles, hybrid motor vehicles, etc., is being vigorously pursued.
The battery degrades as time passes. Therefore, in the case where a battery degrades after many years of use, it becomes necessary to replace the battery.
Japanese Patent Application Publication No. 10-4603 (JP-A-10-4603) discloses a display device for a vehicle-mounted battery which displays information regarding the state of charge and the time of replacement of the battery installed in the vehicle.
This display device has a construction in which a narrow and long display portion that displays the state of the battery using a first division that indicates that the battery is in a good state, a second division that indicates that the battery needs to be replaced, and an intermediate division between the first division and the second division is disposed at a driver's seat.
In recent years, in the field of hybrid motor vehicles, a vehicle capable of plug-in charging whose battery is constructed so as to be able to be charged from an external device is being considered. In the case where the plug-in charging is possible, it is preferable that the battery be charged with as much power as possible so as to restrain the consumption of the fuel, such as gasoline or the like, in terms of reduction of exhaust gas and cost. However, such a manner of use leads to full use of the battery capacity, so that the service life of the battery is more greatly affected than in a vehicle that is not capable of plug-in charging. Therefore, it is becoming increasingly important to diagnose the service life of the battery.
In the case where information regarding such a battery is displayed, a manufacturer, a dealer and a user desire different kinds of information. Manufacturers, and maintenance-repair shops, such as a car dealer or the like, need more detailed information, while it is preferable to provide users with information that is easy to understand.